Sparking plug.



PATENTED JUNE 30, 1903.

W. BARBER. SPARKING PLUG.

APPLICATION FILED AUG. 20, 1902.

N0 MODEL.

mtloeolsesf UNITED STATES Patented June 30, 1903.

, PATENT O EIcE.

WILLIAM BARBER, OF BROOKLYN, NEW YORK, ASSIGNOR TO ADA S. BARBER, OF BROOKLYN, NEW YORK.

SPARKING PLUG.

SPECIFICATION forming part of Letters Patent No. 732,032, dated June 30, 1903.

Application filed August 20, 1902. Serial No. 120,352. (No model.)

T0 whom it may concern:

Be it known that LWILLIAM BARBER,a citizen of the United States of America, residing in the borough of Brooklyn, in the county of Kings, city and State of New York, have invented a certain new and useful Improvement in Sparking Plugs for Use in Explosion- Engines,&c., of which the following is aspecification, such as will enable others skilled. in the art to which it appertains to make and use the same.

The object of my invention is to provide a sparking plug in which the sparking points located within the explosion-chamber will be thoroughly insulated one from the other by a cylinder of porcelain'or like non-carbonizable insulating substance, which insulating non-carbonizable cylinder will be held in position within the metallic portion of the sparking plug by an insulating-cylinder of any suitable insulating material of less frangibility than the non-carbonizable insulating-cylinder, whereby a sparking plug of long life and little liability to damage is produced.

As a rule material which is at once an insulator of electricity in a supreme degree is either extremely frangible, or, if not frangt ble, it is easily carbonizable when subjected to sufiicient heat. The outer ends of sparking plugs when used on automobiles, &c., are frequently subjected to blows by which the insulating thimble or core is fractured, thus instantly rendering the plug useless by reason of the consequent short'circuiting of the electric current by way of the fracture.

The object of my invention is to provide a plug so made that no ordinary blows which it will have to undergo delivered upon it from the outside will be able to affect its insulation. There is no material known, so far as I am aware, which is at once cheap, noncarbonizable, an electric insulator, and practically infrangible. In sparking plugs it is only the outer or exposed portion of the insulation which in order to give the plug durability and long life must possess the quality of infrangibility. On the other hand, it is only the inner end portion thereof which must possess the quality of being extremely non-carbonizable when subjected to a high degree of heat. To make the whole insulating portion of the plug of a material possessing at once both these qualities would render the construction so costly as to render it practicably prohibitive. To make it wholly of material possessing one quality, but not the other, would render its life extremely short,either through carbonization or through fracture. These difficulties I overcome by making the insulating-portion of my plug of an inner part of non-carbonizable but frangible materialsuch as porcelain, mica,&c.- and an outer part of less frangible material, such as compressed fiber, asbestos composition, mica composition, lignum-vitze, ebony, &c., which is of less frangibility than the inner portion of the plug, which is subjected to the heat of the motor-gases. By this construction I am enabled to manufacture a plug at once infrangible, non-carbonizable, and of perfect insulation at an extremely small cost.

Said invention is fully shown and described in the following specification,of which the accompanying drawing forms a part,

wherein similar numerals of reference desig-" nate in all cases like or equivalent parts, such drawing consisting of one figure, (designated as Figure 1,) showing one of my improved sparking plugs in central longitudinal section.

As shown in the drawing, my improved sparking plug consists of a metallic bushing 6, provided on one end with the male screwthread 7, by which the same is at once firmly secured in position in and brought into perfect electrical contact with the walls .of the explosion-chamber of the engine in which the same is desired to be used in the wellknown manner common with sparking plugs, in which the main portion of the engine or motor constitutes one portion of the electric circuit, as is usually the case. This is the form of construction I prefer, although, if desired, both sparking points and the circuits may be insulated from the casing as well as from one another; but as this is no material part of my invention I have not deemed it necessary to show this modification.

The bushing 6 is provided at the end opposite to the male-screw-threaded end 7 with an enlarged orifice provided with a female screw thread adapted to receive a malethreaded .bushing or gland 9, of brass or other suitable metal, such orifice communicating at the inner end with an orifice of somewhat smaller diameter, which extends entirely through the male threaded portion of the plug and in which lies the non-carbonizable insulating cylinder or plug 10, which is provided on the inner end with the flange 11, which abuts against the end of the enlarged orifice, so as to prevent the cylinder or plug 10 from being forced out to the front, while the same is prevented from being forced out to the rear by the like flanged head 12 of the like cylinder 13, formed of suitable non-frangible material having insulating properties, such as papier-mach, which is held in position in the main bushing 6and pressed firmly against the inner end of the porcelain or frangible non-carbonizable plug 10, so as to hold the same firmly in position by such flanged head 12, against which the inner end of the bushing or gland 9 firmly presses when the same is screwed firmly home.

Passing through the two insulating cylinders or plugs 10 and 13 is the metallic rod 14, the head 15 of which adjacent to the inner end of the porcelain plug 10 forms the nega tive or sparkreceiving point or pole of the plug, the positive or spark-throwing point usually consisting of a platinum wire 15, firmly attached to the main bushing 6 in the well-known manner, and the rod 14 is firmly held in position by means of a metallic nut 16, screwed firmly down upon the end of the non-frangible plug 13 by being screwed upon the threaded end of such rod 14, and outside of such nut 16 are a washer 17 and a nut 18 for facilitating the connection therewith of the electric-circuit wire to carry the current.

,By this arrangement it will be seen that while the insulation is perfect and there can be no carbonization of such insulation, inasmuch as that portion subjected to heat is of porcelain or other non-carbonizable material, at the same time the frangible portion of the insulation is thoroughly protected either by metal or the non-frangible insulating cylinder or plug; from breakage.

What I claim, and desire to secure by Letters Patent, is

1. In a sparking plug, the combination with a bushing of metal provided with a male thread on one end and a female thread in an enlarged cavity at the other, of a flanged bushing or cylindrical plug of non-carbonizable frangible insulating material located in the male-threaded portion of thewmetal bushing, a like flanged bushing of infrangible insulating material located in the enlarged cavity of such bushing with its flanged head abutting against the flanged head of the frangible bushing, or plug, a metallic gland screwed into the female thread of the cavity so as to force the flanged heads of the two insulating-plugs together, a metallic rod pass ing through both plugs provided on one end with a head, and on the other with means for securing a securing device thereto, and a sparking point secured to the male-threaded end of the bushing with its point in juxtaposition to the head of the rod, substantially as shown and described.

2. In a sparking plug, the combination with a metallic bushing male-threaded at one end and provided with an enlarged female-threaded cavity at the other, of an insulating-plug having a flange located in the cavity formed of frangible non-carbonizable insulating material, a plug formed of non-frangible insulating material of like form the face of the flange of which abuts against the face of the flange of the frangible plug, and a malethreaded metallic gland for forcing the flange of the non-frangible plug against that of the frangible plug, substantially as shown and described.

3. Inasparking plug, the combination with a metallic bushing adapted to be secured in the wall of the explosion-chamber in electrical connection therewith, of a sparking point secured to the bushing, a rod the inner end of which constitutes the other sparking point located in the bushing, an insulating bushing or plug formed of non-carbonizable insulating material interposed between the rod and the bushing at the inner end, and a like insulating bushing or plug of infrangible insulating material interposed between the rod and the bushing at the outer end, substantially as shown and described.

4. In a sparking plug,the combination with a metallic bushing provided with a sparking point, of a rod passing through the bushing the inner end of which constitutes the other sparking point, an insulating bushing or plug formed of non-carbonizable frangible material insulating the inner end portion of the rod from the bushing, and a like bushing of non-frangible insulating material insulating the outer portion of the rod from the bushing, substantially as shown and described.

5. In asparking plug, the combination with a metallic bushing threaded outside at one end and inside at the other being enlarged at the inner threaded end, of an inner insulating-bushing or cylindrical plug provided with a head or flange located in the female-threaded cavity and formed of porcelain or like noncarbonizable frangible insulating material, a like insulating-bushing or cylindrical plug formed of non-frangible insulating material such as compressed fiber the face of the flanged head of which abuts against the face of the flanged head of the frangible plug, a metallic gland screwed into the female thread of the bushing so as to hold the two insulating bushings orplugs in the bushing, a conducting-rod passing through both insulating-plugs and secured in position therein the inner end of which constitutes one sparking point, and a second sparking point secured to the metallic bushing adjacent to the end of the conductin g-rod,substan tially as shown and described.

IIO

6. ln asparking plug, the combination with an outer main or securing metallic bushing, of an inner insulating plug or bushing formed of frangible non-carbonizable insulating material located in the metallic bushing at its inner end, and an outer insulating plug or bushing of non-frangible insulating material fitting into the outer end of the bushing and abutting against the end of the frangible plug so that the same is concealed and protected, substantially as shown anddescribed.

7. In a sparking plug, the combination with an outer main or securing metallic bushing, of an inner insulating plug or bushing formed of frangible non-carbonizable insulating material located in the metallic bushing at its WILLIAM BARBER.

Witnesses:

C. L. DAVIS, CHAS. A. FERGUSON. 

